Passive optical networks are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities to customers. Passive optical networks are a desirable choice for delivering high speed communication data because they may not employ active electronic devices, such as amplifiers and repeaters, between a central office and a subscriber termination. The absence of active electronic devices may decrease network complexity and cost and may increase network reliability.
Passive optical networks may take a signal from a single incoming fiber and make it available to a number of output fibers. For example, a distribution cable may include 24 optical fibers and may run from a central office to a distribution location, such as an equipment enclosure. At the equipment enclosure, each fiber in the distribution cable may be split into a number of outgoing fibers which are made available to subscribers. For example, passive optical networks may employ 1:2, 1:4, 1:8, 1:16 and 1:32 splitting ratios for each fiber, for making optical data available to subscriber locations.
In traditional gigabit passive optical network a single transmit wavelength and a single receive wavelength are used in each 1:32 split, requiring 32 subscribers to share bandwidth on a single fiber. However, in other systems, such as DWDM systems, dedicated wavelengths are used for each subscriber. Conversion between gigabit and DWDM systems requires substantial reconfiguration of the optical network to take advantage of the dedicated wavelength system. In certain instances, replacing wires leading to subscriber locations would be required. Such re-cabling is costly and time-consuming.
For these and other reasons, improvements are desirable.